In recent years, game devices which utilize image processing technology, whether for home or business use, have come to offer clearer and more realistic images, thereby creating a demand for enhanced and diversified game content.
One area in which game devices of this design are known is that of game devices for driving games (car race games). In driving games, realistic simulation of vehicle motion is of particular importance. Conventional simulations employ a material point model in which the vehicle is placed at a single material point, such as the location of center of gravity. In one known method, the mode of contact (touch) between the vehicle and the ground is determined using this single point. In driving games, creating special effects for vehicle movement has now become essential. Widely employed special effects include dust clouds and tire tread marks.
In games which simulate watercraft, such as boats and jet-skis, a water surface (or ocean surface) constitutes the field through which the object moves. There are some crucial differences between a water surface and a land surface in terms of the characteristics of the field. As may be readily seen from the differences between the two in real space, the spatial position of the course traveled by the vehicle does not change over time, while a water surface ordinarily shifts due to wind and waves.
Accordingly, data for the field in a vehicle game, that is, the three-dimensional space which forms the countryside and road, can be fixed data. In contrast, in the field used in a watercraft game, namely, a water surface, the height of the water surface at any given location must be made to change over time in order to provide a more realistic simulation. Since the adoption of design rules for conventional car games makes it impossible to produce anything but a water surface that is stationary over time, games designed using such rules have monotonous motion and lack a realistic game feel. This is particularly problematic for race games in which several boats compete in terms of speed and position, and poses a significant handicap to creating a game that is interesting.
Despite this state of affairs, there have been no previous proposals for creating shifting water surface (field) image data in a simple and realistic manner. Needless to say, no satisfactory specific proposals have been made regarding methods for accurately determining the mode of contact (touch) with a water surface, or methods for image processing of water surface-related special effects, such as a wake.
Some games which simulate watercraft such as boats and jet-skis employ a craft simulator (rocking component) which the player actually mounts for simulated operation. In this type of game, during the course of the game, the rider, sitting astride a rocking component simulating an actual watercraft, operates the handle or other controls to steer the craft, whereupon a turning radius which generally reflects the steering input, specifically, the steering angle, in the game is determined, the appropriate motion is simulated, and the rocking component tilts in response to the steering angle to provide the simulated experience of turning. According, steering relies on handle control exclusively.
However, when a jet-ski, motor boat, or other watercraft traveling over a water surface attempts to turn smoothly, it is necessary, in addition to controlling the handle, to appropriately shift one's body weight to the left or to the right, as the turning radius is also affected by tilt of the craft induced by shifting body weight.
Conventional craft simulators are operated by handle control exclusively and do not accommodate any shifting of body weight. The rider cannot tilt the rocking component by shifting body weight, making the motion of the craft quite different from that of actual operation. Accordingly, the game lacks realism and fails to provide a realistic and exciting experience.
The present invention was developed with the foregoing in view, and has as an object to provide an image processing device, an image processing method, and a game device which afford more realistic and enhanced representation of a shifting field, such as a water surface, over which a motor boat, jet-ski, or other object travels, and to provide a more interesting watercraft game.
A second object of the present invention is to achieve accurate image processing whereby the mode of contact (touch) between water surface and watercraft in a three-dimensional virtual space can be determined accurately, and errors in height processing for the water surface and watercraft can be eliminated.
A third object of the present invention is to provide an image processing method that can accurately represent boat wakes, objects submerged in the water, and the like with reduced processing.
A fourth object of the present invention is to provide a game device capable of providing a realistic virtual reality experience simulating travel of a craft ridden by the player over the water.
A fifth object of the present invention is to provide a craft simulator whereby the rocking component can be tilted appropriately through a combination of steering and shifts in body weight by the rider, thereby providing a realistic sensation similar to that of turning an actual craft.